Temperature coefficients for the chain dimensions of polystyrene and polymethylmethacrylate

Journal Article · Wed Dec 01 00:00:00 EST 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.465528· OSTI ID:5873216

Boothroyd, A T ^[1]; Rennie, A R ^[2]; Wignall, G D ^[3]

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1. Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom)
2. Polymers and Colloids Group, Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge, CB3 0HE (United Kingdom)
3. Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States)

We have made precise measurements of the unperturbed radius of gyration [l angle][ital S][sup 2][r angle][sup 1/2][sub 0] of polystyrene and polymethylmethacrylate molecules in the melt over the temperature range 120 [degree]C--240 [degree]C by small-angle neutron scattering. Contrary to most previous reports, based on dilute solution measurements, we find that neither polymer exhibits a significant change in dimensions with temperature, and we deduce temperature coefficients, [kappa]=[ital d] ln[l angle][ital S][sup 2][r angle][sub 0]/[ital dT], of (0.0[plus minus]0.1)[times]10[sup [minus]3] K[sup [minus]1] for polystyrene and (0.1[plus minus]0.1)[times]10[sup [minus]3] K[sup [minus]1] for polymethylmethacrylate. These [kappa] values are close to those given by thermoelastic measurements, but are difficult to reconcile with predictions obtained from the rotational isomeric state model.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5873216
• Journal Information: Journal of Chemical Physics; (United States), Vol. 99:11; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
PMMA
TEMPERATURE COEFFICIENT
POLYSTYRENE
CHAINS
MOLECULES
NEUTRON DIFFRACTION
SMALL ANGLE SCATTERING
SOLUTIONS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
COHERENT SCATTERING
DIFFRACTION
DISPERSIONS
ESTERS
MATERIALS
MIXTURES
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYACRYLATES
POLYMERS
POLYOLEFINS
POLYVINYLS
REACTIVITY COEFFICIENTS
SCATTERING
SYNTHETIC MATERIALS
TEMPERATURE RANGE
360602* - Other Materials- Structure & Phase Studies